Pipe coupling seal

ABSTRACT

A pipe coupling device includes an externally threaded first tubular coupling element engaged by an internally threaded second tubular element provided with an outer axially bored end wall and an annular nylon sealing member entrapped between the second element end wall and the confronting end face of the first element. The sealing member includes a tubular body section and a reversely curled outer end flange forming a cuff. In application, the second element is slipped onto the end of a pipe, the sealing member is then positioned on the pipe and the second element slid down to overlie the sealing member, then the first element is slipped onto the pipe, and the coupling elements are screw tightened to longitudinally and radially compress the sealing member into pressure engagement with the faces of the annular cavity delineated by the coupling elements and pipe, wherein a groove is formed on the pipe to lock the coupling in place on the pipe.

BACKGROUND OF THE INVENTION

The present invention relates generally to improvements in mechanical connections and it relates more particularly to an improved fluid-tight pipe coupling device.

The conventional methods and devices for effecting the fluid-tight connection of a pipe to another pipe or a fixture or fitting possess numerous drawbacks and disadvantages. They are highly unreliable, time-consuming and expensive in their application, require the use of special tools and high skills, are of little versatility and adaptability and otherwise leave much to be desired. Many devices and procedures have been proposed to overcome the above drawbacks but these have failed in their purpose and have introduced additional disadvantages.

SUMMARY OF THE INVENTION

It is a principal object of the present invention to provide an improved mechanical coupling device.

Another object of the present invention is to provide an improved pipe coupling device.

Still another object of the present invention is to provice an improved fluid-tight pipe coupling device which may be applied without flaring or threading of the pipe.

A further object of the present invention is to provide a coupling device of the above nature characterized by its simplicity, low cost, high reliability and ruggedness, ease of application, and great versatility and adaptability.

The above and other objects of the present invention will become apparent from a reading of the following description taken in conjunction with the accompanying drawing which illustrates a preferred embodiment thereof.

In a sense the present invention contemplates the provision of a coupling device comprising a first tubular coupling member having an externally threaded first end section provided with an annular end face, an internally threaded second tubular coupling member threadedly engaging the first coupling member threaded section and having an annular shoulder confronting the annular end face and delineating therewith an annular recess, and an annular sealing member nesting in the annular recess and formed of a cold flowable polymeric resin and including an inner tubular body section and a reversely directed outer end flange forming an end cuff on the tubular body section.

According to a preferred form of the improved coupling device as applied to a fluid-tight pipe connection, the second coupling member has an inside threaded face of greater diameter than that of the outside face of the pipe and is provided with an axially bored wall at its inner end which slidably engages the pipe and which has a peripheral shoulder defining conical inside face. The first coupling member is externally threaded at opposite end sections and has a bore equal in diameter to that of the pipe, the second coupling member engaging section of the first coupling member is counterbored to a diameter equal to the outside diameter of the pipe to telescopically receive the pipe. Upon the screw tightening of the coupling members, the annular cavity is longitudinally contracted to longitudinally compress and radially expand the sealing member into fluid-tight engagement with the faces of the annular recess and to form and tightly engage a peripheral groove in the pipe and thereby effect a firm fluid-tight connection to the pipe.

The improved coupling device is highly reliable, rugged, inexpensive and simple, easy to apply and of great versatility and adaptability.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an exploded perspective view of an improved coupling device and associated pipe, embodying the present invention;

FIG. 2 is a medial longitudinal sectional view of the assembled coupling device shown applied to a pipe; and

FIG. 3 is a sectional view taken along line 3--3 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawing which illustrates a preferred embodiment of the present invention, the reference numeral 10 generally designates the improved coupling device which is illustrated as applied to a pipe 11 which may be tube, conduit or other form of pipe and is formed of any suitable material, for example, brass, copper, steel or the like. The coupling device 10 includes a first male coupling member 12 and a second female threaded coupling member 13, the coupling members preferably being formed of a suitable metal, and a sealing and locking member 14 formed of a cold flowable synthetic organic polymeric material such as nylon or the like.

The first coupling member 12 is of tubular configuration including an externally threaded outer end section 16 externally threaded inner end section 17, and an intermediate section 18 between end sections 16 and 17 and having an enlarged tool accommodating portion 19 of polygonal transverse cross section. The coupling member 12 has a uniform axial bore which is counter-bored at its inner end, as at 21, at a radius greater than that of the bore 20 by about the thickness of pipe 11, the main bore 20 being delineated from the counter-bore 21 by a peripheral shoulder 22.

The second coupling member includes an outer nut section 23 having an internal thread 24 engaging the threaded portion 17 and being of a diameter greater than the outside diameter of pipe 11. The inner end of nut section 23 terminates in an end wall, or flange 24 delineating an axial bore 26 of slightly greater diameter than and slidably engaging the pipe 11. The inside face 25 of end wall 24 defines an annular shoulder of conical shape, tapering forwardly outwardly.

The sealing member 14 is of the type described in detail in U.S. Pat. No. 3,299,766 granted Jan. 24, 1967 to W. Gould, et al. and is formed of a cold flowable synthetic organic polymeric material such as nylon or the like. The sealing member 14 includes a tubular body section 27 of slightly greater inside diameter than the outside diameter of pipe 11 and is formed at an end thereof with a rearwardly or reversely extending cuff defining flange or skirt wall 28 abuts the outside face of body section 27 in an area proximate to but spaced from the free end of body section 27 and the flange 28 proximate its junction with body section 27 is curled or beaded to form a curved section 29 spaced outwardly of body section 27. In the assembled coupling device 10 the sealing member 14 is housed or nested in the annular cavity delineated by the end face 30 of threaded section 17 and the confronting shoulder 27 being entrapped between the end face and shoulder.

In attaching the coupling device 10 to the pipe 11 the second coupling member 13 is first applied to the pipe 11 and then the sealing member is slid onto the pipe 11 and inserted into second coupling member 13. Thereafter first coupling member 12 is applied to pipe 11 and advanced until the end of the pipe 11 abuts the shoulder 22. Keeping the pipe 11 so inserted, the female second coupling member 13 is turned in a tightening direction relative to the first coupling member 12 to longitudinally contract the recess housing the sealing member 14 and longitudinally compress and deform and radially expand the sealing member 14 both inwardly and outwardly. With such compression the inside face of sealing member body section advances radially inwardly under pressure to deform pipe 11 and form therein a mating peripheral groove 32 and is in tight mating engagement with the outside face of groove 32. The remainder of the sealing member 14 flows into the shape shown in FIG. 2 with the remaining faces of the pressure deformed sealing member 14 tightly matingly engaging the various surfaces delineating the sealing member housing cavity to thereby effect a firm fluid-tight connection between the coupling member 10 and pipe 11. In the compressed shape of the sealing member 14 the flange 28 is formed into an annular collapsed S-shape joined to the body section 27 by the deformed junction portion 29, the various sections being compressed into a form substantially free of any cavities and filling the sealing member housing cavity in the coupling device 10. The sealing member 14 functions to provide a fluid-tight connection and to anchor the coupling device to the pipe 11. The outer end section 16 may be employed for coupling the device 10 to a matingly threaded fitting or other device in the known manner.

While there has been described and illustrated a preferred embodiment of the present invention, it is apparent that numerous alterations, omissions and additions may be made without departing from the spirit thereof. 

What is claimed is:
 1. A coupling device comprising first tubular coupling member having an externally threaded first end section with an annular end face and a peripheral shoulder formed in the inside face thereof spaced inwardly of and facing in the direction of said annular end face, an internally threaded second tubular coupling member threadedly engaging said first coupling member threaded section and having an annular shoulder confronting said annular end face and delineating therewith an annular recess, an annular sealing member nesting in said recess and formed of a cold flowable polymeric resin and having an initial shape including an inner tubular body section and a reversely directed outer end flange forming an end cuff on said body section, and a pipe, coaxial with and projecting through said second coupling member and sealing member into said first coupling member member and in abutment with said peripheral shoulder, said pipe having a peripheral groove formed in its outer surface disposed substantially axially outwardly of said annular end face in response to said coupling members being screw tightened to longitudinally compress and to deform said sealing member to a shape dissimilar from its inital shape and radially expand it into tight engagement with said peripheral groove of said pipe and the inside face of said second coupling member and substantially fill the cavity defined by said annular end face, annular shoulder, and pipe outside face.
 2. The coupling device of claim 1 wherein the free end of said flange substantially abuts said body section and the remaining portion of said flange is initially outwardly spaced from said body section.
 3. The coupling assembly of claim 1 wherein said sealing member is formed of nylon.
 4. The coupling assembly of claim 1 wherein said first coupling member includes a threaded section at an end opposite said externally threaded first end section.
 5. The coupling assembly of claim 1 wherein said annular shoulder has a conical face tapering outwardly toward said annular end face. 